Appeal No. 2003-1945
Application No. 08/240,877
two-cycle engine block B. The latter consists of
unitary engine cylinder portion 12 and crankcase
portion 13. A valve reed 14, of spring sheet material,
such as, for example shim stock, secured by an anchor
bar 15 and screws 17 to a curved seat 18 formed on the
inner or engine side of the valve block 10.
The curvature of this seat 18 conforms to the
normally flexed condition of the valve reed 14 when the
latter is flexed laterally from its normally straight
position as shown in FIG. 3. The valve reed thus bears
throughout its length against the valve seat, with the
seating bias at the free end of the reed as great as,
or greater than, that throughout the remainder of the
reed. Thus, the reed tends to seat quickly,
effectively, and without float or bounce after each
opening thereof. This provides greatly increased
efficiency, particularly at high speeds, over a reed
valve seated on a conventional flat seat [column 1,
line 55, through column 2, line 2].
In proposing to combine Simpson and McKim to reject
independent claims 78 and 81, the examiner concludes that
[i]t would have been obvious to modify the flexible
valve flap and seat of Simpson et al. (fig. 2) to be
curved because it would have provided for quick
effective seating without float or bounce after each
opening as taught by McKim (col. 1, lines 64-72).
Additionally, the combination of Simpson et al. as
modified by McKim teach[es] the one free portion of the
flexible flap being pressed toward the seal surface in
an abutting relationship therewith when the wearer is
neither inhaling or exhaling and being free to be
lifted from the seal surface during an exhalation (page
2, lines 39-42 of Simpson et al. and fig. 1 of McKim)
[answer, page 5].
As indicated above, McKim teaches that the
floating/fluttering problem targeted by the reed valve disclosed
therein arises during high speed operation of a two cycle engine.
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